1. Field of the Invention
This invention relates to an improvement in ballooning control rings to be used for ring spinning, ring twisting, etc.
2. Description of the Prior Art
As a conventional ballooning control ring to be used for ring spinning, ring twisting, etc., a device disclosed in published Japanese Utility Model Registration Application No. 61-11238, for example, is available. This device, as shown in FIG. 6, comprises an annular body 40 and a fitting member 41 which is fixed to the former by welding. The annular body 40 has at its upper part an oil storing groove 42, extending over almost the entire circumference of body 40, and which is covered with an annular cover 43. In this conventional ballooning control ring, however, oil in the oil storing groove easily leaks out, although the groove has a cover, due to vibration of the machine body during operation and due to other causes. Also, not only is the supplying of oil to the oil storing groove troublesome and time consuming but also "fly waste" easily contaminates oil which has spilled when the oil was supplied, resulting in the deterioration of yarn quality. Moreover, since the fitting member and the annular body which is made of sintered material are fixed together by welding, not only is the welding time consuming and costly but also the welded part breaks easily.